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笔记-Microsoft SQL Server 2008技术内幕:T-SQL语言基础-08 数据修改

时间:2021-07-01 10:21:17 帮助过:6人阅读

INTO dbo.Orders(orderid, orderdate, empid, custid) VALUES(10001, 20090212, 3, A);

SQL Server 2008增强了VALUES语句的功能,允许在一条语句中指定由逗号分隔开的多行记录:

INSERT INTO dbo.Orders
  (orderid, orderdate, empid, custid)
VALUES
  (10003, 20090213, 4, B),
  (10004, 20090214, 1, A),
  (10005, 20090213, 1, C),
  (10006, 20090215, 3, C);

 在SQL Server 2008中还可以用VALUES来构建虚拟表:

SELECT *
FROM ( VALUES
         (10003, 20090213, 4, B),
         (10004, 20090214, 1, A),
         (10005, 20090213, 1, C),
         (10006, 20090215, 3, C) )
     AS O(orderid, orderdate, empid, custid);

 INSERT SELECT语句,注意,目标表必须事先存在。

INSERT INTO dbo.Orders(orderid, orderdate, empid, custid)
  SELECT orderid, orderdate, empid, custid
  FROM TSQLFundamentals2008.Sales.Orders
  WHERE shipcountry = UK;

 INSERT EXEC语句

INSERT INTO dbo.Orders(orderid, orderdate, empid, custid)
  EXEC TSQLFundamentals2008.Sales.usp_getorders @country = France;

 SELECT INTO语句

SELECT orderid, orderdate, empid, custid
INTO dbo.Orders
FROM TSQLFundamentals2008.Sales.Orders;

 SELECT INTO语句会复制来源表的基本结构(包括列名、数据类型、是否允许为NULL及IDENTITY属性)和数据。约束、索引及触发器不会从来源表中复制过来。

BULK INSERT语句

BULK INSERT dbo.Orders FROM c:\temp\orders.txt
  WITH 
    (
       DATAFILETYPE    = char,
       FIELDTERMINATOR = ,,
       ROWTERMINATOR   = \n
    );

带有TOP选项的数据更新

以下代码将删除具有最小订单ID值的50个订单,而不是随机删除50行:

WITH C AS
(
  SELECT TOP(50) *
  FROM dbo.Orders
  ORDER BY orderid
)
DELETE FROM C;

OUTPUT子句

INSERT INTO dbo.T1(datacol)
  OUTPUT inserted.keycol, inserted.datacol
    SELECT lastname
    FROM TSQLFundamentals2008.HR.Employees
    WHERE country = NUSA;

 OUTPUT子句为每个修改过的行返回一个输出行。如果有一个需求,出于审核的目的,需要把修改过的行的一个子集导入一个表:

INSERT INTO dbo.ProductsAudit(productid, colname, oldval, newval)
  SELECT productid, Nunitprice, oldval, newval
  FROM (UPDATE dbo.Products
          SET unitprice *= 1.15
        OUTPUT 
          inserted.productid,
          deleted.unitprice AS oldval,
          inserted.unitprice AS newval
        WHERE SupplierID = 1) AS D
  WHERE oldval < 20.0 AND newval >= 20.0;

 

笔记-Microsoft SQL Server 2008技术内幕:T-SQL语言基础-08 数据修改

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